Damage to freight due to rough handling and road conditions is a costly situation. Rough handling can be caused by slack action within a train transporting freight, usually due to poor train handling or by coupling cars at excessive speeds. Rough handling and irregularities along the transport route create additional expenses by forcing shippers and customers to make considerable expenditures on blocking, bracing, and otherwise attempting to cushion the freight being transported. It is necessary to track instances of rough cargo handling and irregular transport routes to take appropriate measures to protect the cargo.
One system for monitoring conditions under which rough handling may be a problem is the use of hand-held radar for measuring coupling performance with respect to freight cars. This measuring system has several flaws. First, the radar operators are in plain view of the switch crews. Consequently, their normal performance may be altered. Second, there are not enough personnel to constantly monitor coupling speeds for the many freight cars required to be handled in order to ensure good coupling practices twenty-four hours a day, seven days a week. Further, the use of hand-held radar is typically dangerous and requires one person to make the readings and another to record them. This system is also inadequate for use along an entire transport route in which irregularities along either a rail route or paved road may contribute to cargo damage.
One proposed solution suggests the use of monitoring modules located on the vehicle itself for collecting and storing information. Such a system is described in U.S. Pat. No. 5,014,206 to Scribner et al. In this system the location of a vehicle is determined and recorded during the occurrence of events detected by sensors which respond to such an occurrence. The system is associated with navigational units to receive positional information from a navigation system. The location of the vehicle is stored in a data collector on the vehicle. The date and time of the events may also be stored along with the positional information. The position is determined by means of a navigation system such as GPS or LORAN. The stored information is later transported to an information delivery point and downloaded to a data processing system. Here the information is analyzed to determine the exact location and time of the occurrence of the events, such the closure of a passenger door of a taxi or bus, or the pickup of waste by a truck.
As illustrated in FIGS. 1 and 3 of Scribner et al., a truck 10 is equipped with a lift arm sensor 18 and rear door sensor 24 which are coupled electrically to a navigational system such as a GPS type system. The truck also has a passive radio transmitter in the form of tag 30 mounted on it. One such tag is described in U.S. Pat. No. 4,688,026 issued to the same inventors. The purpose of this transmitter is to transmit the truck identification number to a base data receiver/computer unit 32 which may be located at the depot where the truck is returned and housed. When the truck leaves the depot, an RF signal from the receiver/computer unit 32 causes the tag 30 to transmit the truck identification to the receiver/computer 32. The receiver/computer records the time, date and truck identification number. On returning to the depot the tag 30 again transmits the truck identification number to the data receiver/computer unit 32. The information contained in the data collector 28 may then be downloaded into the base receiver unit 32. This information may consist of (1) the identification number of the truck, (2) the day, time, latitude and longitude of each occurrence of the lift arm actuating its sensor, and (3) the day, time, latitude and longitude of each occurrence of actuation of the rear door sensor.
In order to properly protect cargo, the acceleration to which the cargo is subjected must be carefully controlled. U.S. Pat. No. 4,745,564 to Tennes et al. describes an impact detection apparatus for measuring and recording acceleration or other physical quantities experienced by easily damaged items of commerce such as fruit, or electronic computers. A triaxial accelerometer or other suitable sensor produces signals which are stored in a memory along with the times of the events which trigger the accelerometer. This provides an event-time history which later may be read from the memory for analysis after the handling or transportation is completed.
Control of the acceleration to which cargo carrying vehicles are subjected can be exerted as described in U.S. Pat. No. 5,129,605 to Burns et al. This document describes a vehicle positioning system using a plurality of inputs such as a GPS receiver, wheel tachometer, O.S. circuits, transponders and manual inputs from locomotive engineers.
Systems exist for continuously establishing and indicating the location of vehicles such as cars, trucks and boats. Such a system is described in U.S. Pat. No. 4,884,208 to Marinelli et al., which is directed primarily towards theft prevention. In this system a master tracking station receives and stores signals representative of the object identification and the location of the object, and may provide a visual indication of the object identification code and object location. Only vehicle location is detected.
The occurrence of events along a transport route is mapped out in U.S. Pat. No. 4,793,477 to Austill et al. However, this system does not include the use of a transmitter, from which information is downloaded into a central controller via a communication system. Nor is location information fed into a sensing module on the vehicle. Rather, the event location is determined by sensing and recording the degree and direction of track curvature for the rails on which the vehicle is travelling.
None of the aforementioned conventional systems provides the necessary attributes to map, in real-time, a cargo transport route with respect to conditions occurring on that route which may affect the cargo. In order to properly protect the cargo travelling along a route, it is necessary to have a timely knowledge of all conditions which might affect the cargo along that route. Such conditions can be natural or man-made, transient or steady state, and can be caused by interaction with other vehicles or individuals, or by the physical condition of the transport route itself. For such a system to be widely used, it must be effective for a variety of types of transport routes, and be able to supply information regarding all the parts of a given transport route over long distances. Such information should be immediately available upon request or the occurrence of an event of interest (affecting transported cargo) along the transport route. Further, overall conditions along the transport route with respect to such occurrences should be recorded for display and easily updated. The information should be immediately available over long distances without having to approach each vehicle carrying the means for sensing the occurrence of conditions of interest.